Short communication: influence of Staphylococcus aureus intramammary infection on serum copper, zinc, and iron concentrations.

The goal of the present study was to characterize changes in serum trace mineral concentrations in cattle with experimentally induced Staphylococcus aureus mastitis. Nine primiparous Holstein-Friesian cattle were challenged with approximately 150 cfu of Staph. aureus ATCC29740 by intramammary infusion on d 6, 7, and 8 of lactation. Serum Cu, Zn, and Fe concentrations were determined immediately before and at 24, 48, and 72 h after the final intramammary infusion of Staph. aureus. Infection status (cfu/mL of Staph. aureus), milk somatic cell count, and mastitis score were also determined at these times. Infection resulted in a decrease in mean serum Cu, Zn, and Fe concentrations to 89, 83, and 81% of preinfection concentrations at 24 h postchallenge. One-way analysis of variance for repeated measures demonstrated a significant change in serum zinc concentration. The reductions in trace mineral concentrations were of less magnitude than observed following experimental E. coli mastitis.